Knowledge Bank

The AC Stark effect has been observed to be the major cause of broadening in the low temperature multiphoton ionization spectrum of nitric oxide. The effect is seen in these experiments when the NO is seeded in helium carrier gas and expanded through a supersonic nozzle. At rotational temperatures $<$1k, the Stark effect is manifested as an asymmetric line broadening of the three remaining resonances in the (0,0) vibronic band (corresponding to AN=0,+1, $\delta$ +2). Ion yield versus laser intensity measurements near the resonances display radical departures from the usual power dependences predicted by kinetic equations because of the Stark induced shifts. The consequences of this departure will be discussed as will the conditions necessary for observing the effect.